Wound repair in animals follows a well defined time coverage of sequential events, starting with clot formation and culminating with integration of newly synthesized cells and matrix components into the damaged tissue area. The time course of major events in the wound healing process has been described in the studies from many laboratories. Healing in most "normal" cases is essentially complete in approximately 10 days. However, a number of circumstances can greatly extend this time, including infections, nutritional deficiencies, metabolic conditions such as diabetes, genetic defects, such as blood clotting factor deficiencies, and advanced age of the victim.
Many procedures and/or applications have been proposed to enhance healing rates. Antimicrobial agents help healing by blocking infections, but these may, in some instances, also interfere with cellular processes required for wound healing and cause some retardation of rates. Mechanical procedures to insure wound closure, including suturing or bandaging may speed recovery and help prevent excess scar tissue deposition. Chemical treatments with potential stimulatory action on various of the wound healing steps have been utilized with some success, but individual chemical or biochemical agents may be expected to have modes of action on only a limited number of processes within the complex scheme of wound healing reactions, without necessarily stimulating the total process. A number of synthetic or naturally occurring mixtures of components have been proposed in the past to contain a mixture of constituents which are generally stimulatory to the healing process. Convincing evidence supporting these claims and scientific evidence suggesting a physiological basis for the proposed stimulations are lacking.
U.S. Pat. No. 4,296,099 discloses a process for extracting embryonic calf skin which comprises initially grinding the calf skin, extracting same, and separating the resulting extract and lyophilizing the separated extract to provide an extract which exhibits cicatrisive activity and that is employed in cosmetic and pharmaceutical compositions.
Al-Hassan et al (Marine Biology 70, 29-33 (1982)) describe the collection of copious amounts of proteinaceous gel from the epidermal cells of Arabian Gulf catfish (Arius thalassinus, subsequently corrected to Arius bilineatus) when the fish are threatened or injured. Some of the proteins are reported to exist as high molecular weight aggregates. Proteins of 18,000 mol. wt. and 44,000 to 45,000 mol. wt. are prevalent in the gel secretion. The gel is reported to contain several lytic enzyme activities which resemble those of some animal venoms.
Thulesius et al. (Gen. Pharmac. 14: 129-132 (1983)) have reported that both the venom and gel of Arius thallasinus (subsequently corrected to Arius bilineatus) have a large number of protein components with several enzymatic activities which resemble other complex venoms and include esterases, phosphatases and active hemolytic components. Preparations of the gland venom were found to cause contraction of smooth muscle in human umbilical artery and include depressor response in vivo.
The proteinaceous toxin secreted by the epidermal cells of the Arabian Gulf catfish or "skin toxin" was found to produce respiratory distress, agitated behaviors and increased heart rate in rabbits, with an LD.sub.50 of about 1.5 mg protein/kg body weight (Al-Hassan et al. Toxicon. 23(3) 532-534 (1985)). The skin toxin has also been found to cause contraction of sheep renal artery, as well as arteries from other tissues and species (Al-Hassan et al., Toxicon 24 (10): 1009-1014 (1986)). At least two components of the skin toxin have been identified. One component has been described as having acetylcholine-like action which is heat stable and not inactivated by trypsin; possibly being a low molecular weight non-protein component. The activity of the second factor appears to be dependent on prostaglandin synthesis and causes release of prostaglandins from arterial preparations during contraction.
The epidermal gel secretions of Arius thalassinus (subsequently corrected to Arius bilineatus) have also been found, at 4 fold dilution, to inhibit Streptococcus faecalis, Staphylococcus pyogenes, Shigella flexnen, and Saccharomyces cervisiae, thus demonstrating moderate antibacterial activity (Al-Hassan et al., J. Toxicol.--Toxin Reviews 6(1): 1-43 (1987)).
At present, four species of catfish are known to be present in the Gulf: Arius thalassinus, Arius dussumieri, Arius tenuispinis and Arius bilineatus (Al-Hassan et al., J. Nat. Hist. 22, 473-487 (1988)). Although the initial studies leading to the present invention were carried out on fish identified as Arius thalassinus, the species used has been reclassified as Arius bilineatus. Unless otherwise noted, specific examples set forth in the present application refer to Arius bilineatus.